1. Field of the Invention
This invention relates to paper supply mechanisms of the type that are used with ink jet printers, facsimile machines, copiers and the like. More particularly it relates to methods and apparatus for controlling the movement of sheet materials in a roll feed mechanism in which a supply of paper, or other sheet material, is stored within an imaging drum and is arranged to feed to the outer surface of the drum where writing or imaging operations occur.
2. Brief Description of the Prior Art
Countless arrangements have been used to supply paper and other sheet materials automatically to many different types of reproducing machines. In some of these, cut sheets are fed individually from a supply stack, but it is difficult to feed the sheets onto and from the imaging drum, and complex mechanisms are usually required to perform these operations. In other feed systems, paper is fed from a continuous roll into the reproducing equipment and is cut into individual sheets either before or after the imaging operation. In some instances, the continuous supply of paper is cut into individual sheets of the desired length before being fed onto the drum in an effort to overcome the problems associated with feeding a continuous supply onto the drum.
In such a system it is important that the imaged sheet from the supply roll be separated by a smooth cut and not by a tear or a cutter that leaves a jagged edge. The storage of sheet materials in an imaging drum is described in a number of U. S. Pat. Nos. including 866,624 Collier; 4,239,375 to Eisben et al.; 4,231,652 to Moser et al., 4,102,570 to Shimoda; 4,097,138 to Kingsley; 4,068,992 to Buchel, 626,556 to Nolan; and 3,829,208 to van Meljel. None of these patents shows any arrangement for providing a clean cut of the sheet material. In all but the last patent, however, the sheet material is a web used in an intermediate step in a copying process and is returned to the interior of the drum after usage. Those patents disclose no mechanism to shear the sheet material. In the Meljel patent, the used web is either torn off or cut with a jagged edge.
None of these patents discloses any means for monitoring the movement of the sheet material, detecting jams, or indicating the approaching end of the supply of material within the drum.